Boerhavia diffusa Linn. (Syn. Boerhavia repens Linn., Boerhavia procumbens Roxb.; Family Nyctaginaceae) popularly known as Punarnava' is an important rejuvenative drug used in Ayurveda. It is widely distributed throughout India and flourishes during rainy season. The aerial parts then disappear but revive or sprout again next year [Sivarajan, V. V. and Balachandran, I. Ayurvedic drugs and their plant sources; Oxford & IBH publishing Co. Ltd., New Delhi, 1994]. Dried matured whole plant constitutes the drug in Indian Herbal Pharmacopoeia [Handa, S. S., Deepak, M. and Mangal, A. K. Indian Herbal Pharmacopoeia, Regional Research Laboratory, Jammu & Indian Drug Manufacturers Association, Mumbai, 1998, Vol. 1] which also describes its salient macroscopic and microscopic features.
Biodiversity, tribal association [Anand, R. K. Flora and Fauna 1, 167-170 (1995). Medicinal & Aromatic Plants Abstracts 18, 2620 (1996)] and variants [Mathur, A. and Bhandari, M. M. Geobios New Reports, 2, 35-38 (1983)). Medicinal & Aromatic Plants Abstracts 5, 0643 (1983), Varma, S. K. Biological Bulletin of India 5, 50-52 (1983). Medicinal & Aromatic Plants Abstracts 6, 0467 (1984)] of Boerhavia diffusa and chemotaxonomic findings [Bramadhayalaselvam, A. and Rajasekaran, K. Journal of Economic and Taxonomic Botany, 18, 499-500 (1994)] in Nyctaginaceae have been discussed. Many rotenoids have been isolated from the roots of the plant [Ahmed, M., Datta, B. K. and Rouf, A. S. S. Phytochemistry 29, 1709-1710 (1990); Kadota, S., Lami, N., Tezuka, Y. and Kikuchi, T. Chemical and Pharmaceutical Bulletin 37, 3214-3220 (1989); Lami, N., Kadota, S., Tezuka, Y. and Kikuchi, T. Chemical and Pharmaceutical Bulletin 38, 1558-1562 (1990); Lami, N., Kadota, S. and Kikuchi, T. Chemical and Pharmaceutical Bulletin 39, 1863-1865 (1991)]. These include a series of boeravinones viz., boeravinone A, boeravinone B, boeravinone C, boeravinone D, boeravinone E and boeravinone F. Punarnavoside, a phenolic glycoside, is reportedly present in roots [Jain, G. K. and Khanna, N. M. Indian Journal of Chemistry 28B, 163-166 (1989); Seth, R. K., Khanna, M., Chaudhary, M. Singh, S. and Sarin, J. P. S. Indian Drugs 23, 583-584 (1986)].
Three flavonol glycosides viz., eupalitin 3-O-β-D-galactopyranosyl-(1→2)-R-D-glucopyranoside, eupalitin 3-O-β-D-galactopyranoside and 6-methoxykaempferol 3-O-β-D-(1→6) robinoside from the Boerhaavia repens whole plant [LL J., LL H., Kadota, S. and Namba, T. Journal of Natural Products 59, 1015-1018 (1996)] and a C-methyl flavone have been isolated from Boerhaavia diffusa roots [Indian Journal of Chemistry 23B, 682-684 (1984)]. Also isolated from Boerhaavia diffusa roots are two lignans viz., liriodendrin and syringaresinol mono-β-D-glycoside [Lami, N., Kadota, S., Kikuchi, T. and Momose, Y. Chemical and Pharmaceutical Bulletin 39, 1551-1555 (1991)]. Presence of a purine nucleoside hypoxanthine 9-L-arabinose [Ojewole, J. A. O. and Adesina, S. K. Fitoterapia 56, 31-36 (1985)] a dihydroisofuroxanthone-borhavine [Ahmed, B. and Yu, C. P. Phytochemistry 31, 4382-4384 (1992)] and phytosterols [Kadota, S., Lami, N., Tezuka, Y. and Kikuchi, T. Chemical and Pharmaceutical Bulletin 37, 3214-3220 (1989); Kadota, S., Lami, N., Tezuka, Y. and Kikuchi, T. Journal of Pharmaceutical Sciences 76, S201 (1987)] from the plant are reported.
Hepatoprotective property of Boerhavia diffusa has been investigated and confirmed by different research workers [Chakraborti, K. K. and Handa, S. S. Indian Drugs 27, 161-166 (1989); Chandan, B. K., Sharma, A. K. and Anand, K. K. Journal of Ethanopharmacology 31, 299-307 (1991); Rawat, A. K., Mehrotra, S., Tripathi, S. C. and Shome, U. Journal of Ethanopharmacology 56, 61-66 (1997); De, S., Ravishankar, B. and Bhavsar, G. C. Indian Drugs 30, 355-363 (1993)]. The plant possesses potent antifibrinolytic and antiinflammatory activities and is recommended for the treatment of IUD menorrhagia [Barthwal, M. and Srivastava, K. Advances in Contraception 7, 67-77 (1991); Barthwal, M. and Srivastava, K. Advances in Contraception 6, 113-124 (1990)]. Boerhaavia diffusa is also reported to possess antihypertensive properties [Ramabhimaiah, S., Stalin, D. and Kalaskar, N. J. Indian Drugs 21, 343-344 (1984)] for which both its angiotensin converting enzyme inhibition [Aftab, K., Usmani, S. B. and Ahmad, S. I. Hamdard Medicus 39, 44-54 (1996); Medicinal & Aromatic Plants Abstracts 18, 2920 (1996)] and Ca2+ channel blocking effects [Hansen, K., Nyman, U. Smith, U. W., Andersen, A., gudiksen, L. Rajasekharan, S and Pushpangadan, P. Glimpses of Indian Ethnopharmacology (ed. Pushpangadan, P.) 263-273 (1995)] may be responsible. The drug's usefulness in nephritic syndrome has been demonstrated in albino rats [Singh, A., Singh, R H., Singh, R G., Misra, N., Vrat, S., Prakash, M. and Singh, N. Indian Drugs 26, 10-13 (1988)] as well as in humans [Singh, R. P., Shukla, K. P., Pandey, B. L., Singh, R. G., Usha and Singh, R. H. Journal of Research and Education in Indian Medicine 11, 29-36 (1992)]. Purified extracts of the plant increased amylase [Goswami, P. and Sharma, T. C. Journal of Research in Ayurveda and Siddha 13, 48-55 (1992)] and ATPase [Goswami, P. and Sharma, T. C. Journal of Research in Ayurveda and Siddha 13, 135-140 (1992)] activities while decreasing catalase activities in vitro. Roots of the plant also exhibited anticonvulsant properties [Adesina, S. K. Quarterly Journal of Crude Drug Research 17, 84-86 (1979); Akah, P. A. and Nwambie, A. I. Fitoterapia 64, 42-44 (1993). The drug has been found to be devoid of tetratogenic effect [Singh, A., Singh, R G., Singh, R. H., Misra, N. and Singh, N. Planta Medica 57, 315-316 (1991)]. Punarnavoside had antifibrinolytic activity in monkeys [lain, G. K. and Khanna, N. M. Indian Journal of Chemistry 28B, 163-166 (1989). Liriodendrin blocked Ca2+ channel in frog heart single cells [Lami, N., Kadota, S., Kikuchi, T. and Momose, Y. Chemical and Pharmaceutical Bulletin 39, 1551-1555 (1991)] and hypoxanthine 9-L-arabinoside produced depressor and negative chronotropic effects in rats and cats [Ojewole, J. A. O. and Adesina, S. K. Fitoterapia 56, 31-36 (1985)]. A methanol extract from the whole plant of Boerhaavia repens was found to inhibit bone resorption induced by parathyroid hormone (PTH) in tissue culture [LL J., LL H., Kadota, S. and Namba, T. Journal of Natural Products 59, 1015-1018 (1996)]. Bioactivity guided fractionation of the methanol extract indicated the concentration of activity in the n-butanol soluble fraction. From the n-butanol soluble fraction eupalitin 3-O-β-D-galactopyranoside was isolated and was found to have significant (p<0.001) inhibition of bone resorption induced by parathyroid hormone (PTH) in tissue culture. The activity shown by eupalitin 3-O-β-D-galactopyranoside was more than that exhibited by lpriflavone, a clinically used natural product derivative for the treatment of osteoporosis in Japan and Italy, under identical conditions.
The compound eupalitin 3-O-β-D-galactopyranoside was isolated by Li et al [LL J., Li, H., Kadota, S. and Namba, T. Journal of Natural Products 59, 1015-1018 (1996)] as follows: The shade-dried Boerhaavia repens whole plant (1.2 kg) was chopped into small pieces and refluxed with methanol for 3 h (900 ml×2). The total filtrate was evaporated under reduced pressure to obtain a dark green mass, and this extract was suspended in distilled water and partitioned with chloroform and n-butanol successively. The n-butanol soluble fraction was purified repeatedly by preparative TLC to yield eupalitin 3-O-β-D-galactopyranoside (14.4 mg, 0.0012%).